Correlation between micro-structural properties and ionic conductivity of Li1.5Al0.5Ge1.5(PO4)3 ceramics

▶ Li1.5Al0.5Ge1.5(PO4)3 ceramics were prepared from amorphous powders, which had been synthesized by the flash creation method. ▶ A maximum total conductivity of 2 × 10−4 S/cm at room temperature was found for a sample sintered at 750 °C for 2 h. ▶ The classical brick layer model does not adequately describe the ion transport through the grain boundaries. ▶ The predictions of a finite-element approach taking into account the limited contact area between the grains are in good agreement with the experimental ratio of grain and grain boundary resistance.